Groatman, 88, died after being taken off of life support Thursday afternoon.

Anne Castagna, 43, of Brooklawn, is accused of poisoning her grandmother-in-law with antifreeze.

Prosecutor Sean Dalton announced that new charges were filed shortly after Groatman's death.

Bail was reset to $350,000 full cash by Superior Court Judge Walter L. Marshall Jr. Castagna was served with the new charge at the Gloucester County Jail in the presence of her attorney, Fred Last.

Castagna could appear in court as early as Aug. 31, according to Dalton.

Conviction on a first-degree murder charge carries with it a sentence of from 30 years to life in state prison.

Due to an extensive and ongoing investigation, officials say they have reason to believe Castagna intentionally poisoned Groatman, for whom she was the caregiver.

Castagna and her husband have apparently resided with Groatman for about a decade.

Authorities said that when the poisoning occurred, Groatman was at the Deptford Center for Rehabilitation and Healthcare recovering from injuries sustained in a fall.

Calls to the center for comment were not immediately returned.

Castagna had apparently visited Groatman at the rehab facility on Aug. 19, the same day Groatman was discovered unconscious and unresponsive in her room.

Staff Photo by Tim Hawk/Gloucester County TimesGloucester County Prosecutor Sean Dalton speaks at a press conference Thursday afternoon in Woodbury, announcing that the charges against Anna Castagna will be upgraded to first-degree murder.

“She was subsequently taken to the emergency room at Underwood-Memorial Hospital, where she underwent testing to determine the cause of her symptoms,” Dalton said. “It was determined by the emergency room staff at Underwood-Memorial Hospital that she had ethylene glycol — the main ingredient in antifreeze — in her system.”

The substance can be fatal to humans and animals.

“The investigation further determined that the accused had, in the time period leading up to this incident, researched the effects of ingesting anti-freeze on the human body,” Dalton revealed, although he said could not disclose the manner in which this was determined.

Dalton said Groatman was otherwise in good health for her age.

An autopsy will be performed on the victim and the investigation will remain ongoing.

Groatman is survived by children, grandchildren, and great-grandchildren.